• Communications of Mathematical Education
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• v.29 no.3
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• pp.513-532
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• 2015

In order to suggest desirable management of college mathematics for freshmen in middle level engineering college, we analyse the change of mathematics recognition between 2011 year and 2015 year freshmen who took college scholastic ability test which are based on the national mathematics curriculum 7th and 7th revision, respectively. In A university, 2011 year and 2015 year engineering freshmen were taken basic mathematical ability test and given the survey for the recognition of mathematics and college mathematics. Research results are as follows: First of all, middle level engineering freshmen were poor at basic mathematical ability. The change of mathematics recognition appeared in the level of mathematics ability and the effort for college mathematics class. Moreover middle level engineering freshmen recognize college mathematics as a basic subject for engineering and hope teacher-directed learning in college mathematics class. For the success of college mathematics in engineering college, this study suggests basic mathematical ability test and the survey for the recognition of mathematics and college mathematics. We also suggest that college mathematics class must be focused on basic mathematical ability improvement and self-directed learning.

• Journal of Veterinary Clinics
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• v.26 no.4
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• pp.311-316
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• 2009

The purpose of this meta-analysis was to collect data from the literatures reporting prevalence of canine heartworm (HW) infection in an effort to emphasize the preventive importance of the disease and to serve as baseline data for further studies related to the disease management. Fourteen studies regarding the prevalence of HW infection published during the 1996-2007 were identified using the meta-analytic approach, involving a total of 1,790 cases by microfilarial test and 3,277 cases by enzyme-linked immunosorbent assay (ELISA) antigen test for adult worms. Data analysis was performed separately for pet and military dogs. The overall apparent prevalence of HW infection in pet dogs by microfilarial test and ELISA was 11.7% (183/1,563) and 16.5% (379/2,302), respectively (p < 0.001). No significant difference in prevalence by microfilaria and ELISA was observed between sexes whether assessed by data separately or pooled together. Compared to before 2000, the prevalence by microfilaria after 2000 has increased from 2.5% to 13.1% (p < 0.001), and the rate of adult worm has also increased from 9.9% to 20.3% (p < 0.001). The prevalence determined by ELISA was found to increase with age: 20.7% (n = 1,003) of dogs older than 2 years were positive, compared with 5.0% of dogs (n = 701) under 2 years of age (p < 0.001). Also, outdoor dogs showed significantly higher prevalence than indoor dogs (37.9% versus 3.4%; p < 0.001). For military dogs, the overall prevalence was 38.3% (87/227; 95% CI, 32.1 - 44.7%) by microfilarial test and 38.5% (375/975; 95% CI, 35.4 - 41.6%) by ELISA. This rate was significantly higher than that of pet dogs (p < 0.001). Occult infection rate of 37.5% and 66.7% was found in pet and military dogs, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.4068-4076
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• 2013

The wheel-rail interaction forces are influenced by the velocity of vehicle, wheel load, alignment (curve radius, cant etc). For the safety of track structure, it is required to evaluate the influences for track and influential factors. Recently, the HEMU 430-X, which was developed by Next Generation High-Speed Rail Development R&D Project, achieved 421.4km/h in a test run of Daegu.Busan section of the Gyeongbu high speed rail on March in 2013. In the case of additional speed-up test on Test-Bed Section(Gongju.Jeongeup: KP 100~128km Osong starting point), the analysis of track forces is required for outer rail by the increase of dynamic force and centrifugal force of vehicle. In this paper, the vehicle speed variation on HSL line is evaluated by TPS analysis considering the tractive effort of HEMU 430-X, tested running resistance and alignment of Honam HSR. And the track forces are evaluated by centrifugal force and impact factor on curved track.

• Journal of Environmental Science International
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• v.25 no.4
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• pp.505-516
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• 2016

With the development of nanotechnology, nanomaterials are used in various fields. Therefore, the interest regarding the safety of nanomaterial use is increasing and much effort is diverted toward establishment of exposure assessment and management methods. Occupational exposure limits (OELs) are effectively used to protect the health of workers in various industrial workplaces. This study aimed to propose an OEL for domestic multi-walled carbon nanotubes (MWCNTs) based on animal inhalation toxicity test. Basic procedure for development of OELs was examined. For OEL estimation, epidemiological study and quantitative risk assessment are generally performed based on toxicity data. In addition, inhalation toxicity data-based no observed adverse effect level (NOAEL) and benchmark dose (BMD) are estimated to obtain the OEL. Three different estimation processes (NEDO in Japan, NIOSH in USA, and Baytubes in Germany) of OELs for carbon nanotubes (CNTs) were intensively reviewed. From the rat inhalation toxicity test for MWCNTs manufactured in Korea, a NOAEL of $0.98mg/m^3$ was derived. Using the simple equation for estimation of OEL suggested by NEDO, the OEL of $142{\mu}g/m^3$ was estimated for the MWCNT manufacturing workplace. Here, we used test rat and Korean human data and adopted 36 as an uncertainty factor. The OEL for MWCNT estimated in this work is higher than those ($2-80{\mu}g/m^3$) suggested by previous investigators. It may be greatly caused by different physicochemical properties of MWCNT and their dispersion method and test rat data. For setting of regulatory OELs in CNT workplaces, further epidemiological studies in addition to animal studies are needed. More advanced technical methods such as CNT dispersion in air and liquid should be also developed.

• Journal of National Security and Military Science
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• s.7
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• pp.271-303
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• 2009

"Ubiquitous sensor network" definition is this-Someone attaches electro-magnetic tag everything which needs communication between man to man, man to material and material to material(Ubiquitous). By using attached every electro-magnetic tag, someone detects it's native information as well as environmental information such as temperature, humidity, pollution and infiltration information(Sensor). someone connects it realtime network and manage generated information(Network). 21st century's war is joint combined operation connecting with ground, sea and air smoothly in digitalized war field, and is systematic war provided realtime information from sensor to shooter. So, it needs dramatic development on watch reconnaissance, command and control, pinpoint strike etc. Ubiquitous computing and network technologies are essential in national defense to operate 21st century style war. It is possible to use many parts such as USN combined smart dust and sensor network to protect friend unit as well as to watch enemy's deep area by unmanned reconnaissance, wearable computer upgrading soldier's operational ability and combat power dramatically, RFID which can be used material management as well as on time support. Especially, unmanned watch system using USN is core part to transit network centric military service and to get national defense efficiency which overcome the dilemma of national defense person resource reducing, and upgrade guard quality level, and improve combat power by normalizing guardian's bio rhythm. According to the test result of sensor network unmanned watch system, it needs more effort and time to stabilize because of low USN technology maturity and using maturity. In the future, USN unmanned watch system project must be decided the application scope such as application area and starting point by evaluating technology maturity and using maturity. And when you decide application scope, you must consider not only short period goal as cost reduction, soldier decrease and guard power upgrade but also long period goal as advanced defense ability strength. You must build basic infra in advance such as light cable network, frequency allocation and power facility etc. First of all, it must get budget guarantee and driving force for USN unmanned watch system project related to defense policy. You must forwarded the USN project assuming posses of operation skill as procedure, system, standard, training in advance. Operational skill posses is come from step by step application strategy such as test phase, introduction phase, spread phase, stabilization phase and also repeated test application taking example project.

• Korean journal of aerospace and environmental medicine
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• v.31 no.3
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• pp.77-81
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• 2021

Purpose: The United States of America have pre-migration screening program are mandated through legislation. The one of purpose of this program is to prevent the importation of certain communicable diseases. Examinations of migration applicants are performed by panel physicians who are licensed physicians in the countries of origin that have agreements with the government departments of the country of destination to undertake this activity. In recent decades, the number of US migrants has increased, however COVID-19 impacted this trend of international migrants. The Aim of this study is to examine trends of US applicants and outcomes of tuberculosis and sexual transmitted infections (STIs) screening in South Korean applicants for US visa. Methods: A total of 4,442 applicants participated in US visa health check-up in 2016 to 2020. Results: The numbers of applicant for US visa in males and females was 1,814 and 2,628. The positive results in tuberculosis and STIs screening was noted with 0.66% in nontuberculous mycobacteria (NTM), 0.03% in tuberculosis, 0.03% in gonorrhea, 0.08% in syphilis, and 0.74% in chlamydia. The age groups of 2 to 14 years showed higher positive rate (13.89%) in tuberculin skin test (TST) tests compared to the rate of interferon gamma release assay (IGRA) tests (0.44%, P<0.001). The positive ratio of NTM and abnormal chest X-ray (CXR) which required sputum tests among the applicants over 15 years old has trends to increase with age. The age groups of over 70 years showed high positive rate in NTM and abnormal CXR (4.10%, 20.51%). However, ages 15 to 49 years groups showed 0.00% to 0.30% in NTM and 1.08% to 3.91% in abnormal CXR. In the study population, the positive rates of STIs were 0.03%, 0.08%, and 0.74% in gonorrhea, syphilis, and chlamydia, respectively. Among the participants who underwent sputum smears and cultures were just 1 case of active tuberculosis (0.03%) and 25 cases of NTM infection (0.66%). Conclusion: This study found that rate of positivity in tuberculosis and STIs screening among South Korean applicants for US visa in 2016 to 2020. Regarding tuberculosis, the positivity of CXR among the aged 15 to 59 years applicants was lower than that among over 60 years old. Among 2 to 14 years, positivity of IGRA was very low. And IGRA test can reduce effort of further evaluation compared to TST test in South Korea, so IGRA test among young adults can be useful. High positive rates in STI among young adult could result in high active sexuality, especially chlamydia infection is most common. Therefore Chlamydia polymerase chain reaction should be considered formal protocol among the Korean applicant for US visa.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.102-109
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• 2023

In realizing a hydrogen society, it is important to secure the safety of the hydrogen refueling station, which is the facility where consumers can easily meet hydrogen. The hydrogen refueling station consists of compressed gas facilities that store high-pressure hydrogen, and there is a risk that the high-pressure compressed gas facility will rupture due to a fire explosion due to hydrogen leakage in the facility or the influence of surrounding fires. Accordingly, the Korea Gas Safety Corporation is making every effort to find out risk factors from the installation stage, reflect them in the design, and secure safety through legal inspection. In this study, a TNT explosion demonstration test using a protection wall was conducted to confirm the safety effect of the protection wall installed at the hydrogen refueling station, and the empirical test results were compared and verified using FLACS-CFD, a CFD program. As a result of the empirical test and CFD analysis, it was confirmed that the effect of reducing the explosion over-pressure at the rear end of the protection wall decreased from 50% to up to 90% depending on the location, but the effect decreased when it exceeded a certain distance. The results of the empirical test and computer analysis for verifying the safety of the protection wall will be used in proposals for optimizing the protection wall standards in the future.

• Journal of the Korean Home Economics Association
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• v.8 no.1
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• pp.198-215
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• 1970

The basic purpose of this study is to explore the household economic effects on home administration. The major goals of home administration is to promote mental and physical welfare of the family members. In order to realize mental and physical welfare, the stability and satisfaction is needed. And to promote stability and satisfaction, the efficiency must be accomplished and the efforts is required. So the four variables to measure home administration situation are as follows. 1) The degree of the stability 2) The degree of the efficiency 3) The degree of the efforts 4) The degree of the satisfaction. The factor of Household economic level is the size of the family's money income. Although size of income is not the bases for either standard of living or Socioeconomic status, it is closely related to both. To solve this problem. Some hypotheses are specified as follows. Hypotheses I The degree of the stability is different among the groups by income level. The group which is high income level will be more stable than low income level. Hypothesis II The degree of the efficiencies different among the groups by income level. The group which is high income level will be more efficient than low income level. Hypothesis III The degree of the efforts is different among the groups by income level. The group which is high income level will more effort than low income level. Hypothesis IV The degree of the satisfaction is different among the groups by income level. The group which is high income level will feel more satisfaction than low income level. In order to test those hypotheses random selection of 190 subjects from the four girls high schools in Seoul was made, and the parents of the students reported their home administration situation. The results of this study show that; 1) the group which is high income level revealed more stability than low income level. The differences of each group are revealed very significant. 2) The differences of the degree of the efficiency among the groups are unsignificant. 3) the group which is high income level revealed more effort than low income level. The differences of each group are revealed significant. 4) The group which is high income level revealed more satisfaction than low income level. The differences of each group are particularly significant. So the conclusion can be drawn from this study. Every group by income level revealed significant differences in home administration. So the household economy greatly effects on home administration.

• Korean Journal of Occupational Health Nursing
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• v.10 no.2
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• pp.174-182
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• 2001

This study was performed to find out the differences between noise levels of hospital wards and the nurses efforts for noise management in some general hospitals. The hospital wards selected were the intensive care unit(ICU), the emergency room(ER), the nursery room(NR), the internal medicine(IM), the general surgery(GS) among the 5 general hospitals located in Seoul. The data were collected from August 3 to September 13, 1999 through questionnaire survey and noise measurement in each nursing station of hospital wards. Data analysis was done by SPSS 8.0 package among the 305 questionnaires and 24 hours monitored noise levels. Frequency, Chi-square and ANOVA test were used. The study results were as belows: 1. The noise level measured by 24 hours monitoring survey were exceeded on the standard limit in all the hospital wards. Data also showed that noise levels were significantly different in each ward among the three shifts working duties. 2. The subjects were all female nurses. They were mostly working in the ICU ward(28.9%). They were 26~30 years old (43.9%), junior college graduates(57.0%), working for 1~5 years(55.1%) as staff-nurse(85.6%). There were no significant differences between hospital wards and general characteristics of nurses. 3. The noise levels perceived by nurses were regarded as 'Highly noisy'(56.4%), especially during the 11:30 and 15:30 (30.2%) o'clock. Data also showed that noise education was not ever given to nurses(89.9%). Nurses also responded that they hardly put an effort to reduce noise level(54.8%). However, there were significant differences between wards and noisy working time, experience of noise education and level of effort for noise reduction. 4. Nurses also perceived the ventilator alarm and EKG-alarm as the most disturbing sounds in the ICU, human voice and telephone ringing in the ER, human voice and EKG-alarming in the NR, human voices and telephone ringing in IM and GS both wards respectively in order. There were significant differences between hospital wards and noise making factors. 5. Nurses were shown that they regarded highly 'Sound reduction of the human voice', 'Careful handling on medical instruments', and 'Immediate appliances on alarming materials' as the practical method for noise management. There were significant differences between hospital wards and behavioral practical efforts for noise management. According to that results, the statistical differences were shown in the 24 hour monitored noise levels in each ward. Also, nurses perceived the noise severity differently and they approached variously on the practical efforts for noise reduction in each ward. Thus, author thinks that concrete and systematic endeavor will be necessary for noise reduction and management in hospitals for better working and healing environment for both of patients and staffs.

• Korean Journal of Social Welfare Studies
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• v.44 no.3
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• pp.347-369
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• 2013

Quality of life for people living with HIV/AIDS is significant as it concerns the treatment process, survival rate, HIV/AIDS prevention and treatment as well. Prevalent prejudice in our society significantly lowers the quality of patient's life. There is a need for an intervention and the effort to eliminate the stigma in order to lessen the negative effects as well. However, there are very few researches that examine the quality of life when it comes to people living with HIV/AIDS; even less when it comes to research that examines the stigma that affects the quality of life negatively. Therefore, this research seeks to verify the moderating effects of social support that seek to eliminate the stigma upon the quality of life in people living with HIV/AIDS. Research had been conducted with 102 people living with HIV/AIDS and the balancing effect of the social effort was verified through hierarchical regression analysis and a simple slope test. As the result of the research, control variables such as educational level and whether the patient has a job or not have significant effect and the stigma that the patient is aware of has significant negative effect. Social support had positive effect in quality of life and that it has a moderating effect on stigma which in turn affects the quality of life. Based on these results, social work related implications that were suggested are as follows; need for information and education as to better the quality of life for people living with HIV/AIDS and eliminate the social stigma and that group support program based on the local community which is needed for social support. Further research was advised based on the limitations of this research.