• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.81-87
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• 2018

This research was done to investigate the bioreduction characteristics of perchlorate in raw sewage because sewage contains biodegradable organics and various microorganisms for biological perchlorate reduction. Two different types of sewage were tested for biological perchlorate reduction in the flasks. Sewage A was collected from the screening equipment and sewage B was collected from the primary settlement in the municipal wastewater treatment facilities. Perchlorate was completely reduced within 72hours from 8.2 and 10.4 mg/L in the sewage A and sewage B flask tests. When perchlorate and nitrate were added in sewage A, both perchlorate and nitrate were reduced. However, perchlorate and nitrate removal rates were 9.3% and 64.0% at 72hours in sewage B. Perchlorate reduction was significantly inhibited by high salinity(0.5% NaCl) in the sewage A and B. These results showed the sewage has potential for the biological perchlorate reduction in the sewage pipe.

• Journal of information and communication convergence engineering
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• v.20 no.1
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• pp.58-64
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• 2022

Breast ultrasonic reading is critical as a primary screening test for the early diagnosis of breast cancer. However, breast ultrasound examinations show significant differences in diagnosis based on the difference in image quality according to the ultrasonic equipment, experience, and proficiency of the examiner. Accordingly, studies are being actively conducted to analyze the texture characteristics of normal breast tissue, positive tumors, and malignant tumors using breast ultrasonography and to use them for computer-assisted diagnosis. In this study, breast ultrasonography was conducted to select 247 ultrasound images of 71 normal breast tissues, 87 fibroadenomas among benign tumors, and 89 malignant tumors. The selected images were calculated using a statistical method with 21 feature parameters extracted using the gray level co-occurrence matrix algorithm, and classified as normal breast tissue, benign tumor, and malignancy. In addition, we proposed five feature parameters that are available for computer-aided diagnosis of breast cancer classification. The average classification rate for normal breast tissue, benign tumors, and malignant tumors, using this feature parameter, was 82.8%.

• Journal of Radiation Protection and Research
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• v.48 no.4
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• pp.167-174
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• 2023

Background: A nondestructive test is commonly used to inspect the surface defects and internal structure of an object without any physical damage. X-rays generated from an electron accelerator or a tube are one of the methods used for nondestructive testing. The high penetration of X-rays through materials with low atomic numbers makes it difficult to discriminate between these materials using X-ray imaging. The interaction characteristics of neutrons with materials can supplement the limitations of X-ray imaging in material discrimination. Materials and Methods: The radiation image acquisition process for air-cargo security inspection equipment using X-rays and neutrons was simulated using a GEometry ANd Tracking (Geant4) simulation toolkit. Radiation images of phantoms composed of 13 materials were obtained, and the R-value, representing the attenuation ratio of neutrons and gamma rays in a material, was calculated from these images. Results and Discussion: The R-values were calculated from the simulated X-ray and neutron images for each phantom and compared with those obtained in the experiments. The R-values obtained from the experiments were higher than those obtained from the simulations. The difference can be due to the following two causes. The first reason is that there are various facilities or equipment in the experimental environment that scatter neutrons, unlike the simulation. The other is the difference in the neutron signal processing. In the simulation, the neutron signal is the sum of the number of neutrons entering the detector. However, in the experiment, the neutron signal was obtained by superimposing the intensities of the neutron signals. Neutron detectors also detect gamma rays, and the neutron signal cannot be clearly distinguished in the process of separating the two types of radiation. Despite these differences, the two results showed similar trends and the viability of using simulation-based radiation images, particularly in the field of security screening. With further research, the simulation-based radiation images can replace ones from experiments and be used in the related fields. Conclusion: The Korea Atomic Energy Research Institute has developed air-cargo security inspection equipment using neutrons and X-rays. Using this equipment, radiation images and R-values for various materials were obtained. The equipment was reconstructed, and the R-values were obtained for 13 materials using the Geant4 simulation toolkit. The R-values calculated by experiment and simulation show similar trends. Therefore, we confirmed the feasibility of using the simulation-based radiation image.

• The Korean Journal of Food And Nutrition
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• v.20 no.2
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• pp.226-239
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• 2007

The purpose of this study was to identify the problems related to the purchasing processes of school foodservices that should be corrected for the food service safety, by examining the purchasing processes and the status of supplier selection. A questionnaire was given to 300 dietitians working at self-operated food services. Ninety-eight responses, excluding incomplete answers, were used for the statistical analysis. The survey consisted of three parts: the general characteristics of the school foodservice and dietitian, purchasing processes and supplier selection, and the purchase specifications. We found that 84% of the contract was made by informal purchasing, and the contract period was 6 months or one year. For supplier selection, problems related to the document screening systems were the superficiality of the content(45.7%) and the absence or lack of clarity of the appraisal criteria(34.8%). The important factors for the facility and equipment standards of suppliers were included unclear evaluation methods for content(41.1%) and inappropriate appraisal lists(21.1%), while unclear evaluation methods for content(41.9%) and absence or lack of clarity of the appraisal criteria(20.4%) were the problems pertaining to the supplier evaluation checklist. When using the Food Labeling Standards to select suppliers, confirmation of the sell-by date and the storage method had the highest score at 3.85 out of 5. For supplier selection, only 25% of the contract was made by using the purchase specifications. The levels of satisfaction of with Kimchi and rice cakes suppliers were significantly different according to employment type and educational background, respectively. Depending on working experiences, satisfaction was significantly different for the use of document screening, as a standard for the selection and management of suppliers, and for the facility and equipment standards of suppliers, The use of purchase specifications was different by employment type, while the use of purchase specifications for contracts was different by working experience. These results imply that the specialization of suppliers is necessary to unsure food safety. Therefore, the objective methods to evaluate the suppliers should be developed by the government, and appropriate education programs for dietitians should be prepared to enhance the utilization of purchase specifications.

• Journal of the Korea Society for Simulation
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• v.29 no.4
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• pp.33-46
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• 2020

The purpose of Electronic warfare is to disturbe, neutralize, attack, and destroy the opponent's electronic warfare weapon system or equipment. Suppression of Enemy Air Defense (SEAD) mission is aimed at incapacitating, destroying, or temporarily deteriorating air defense networks such as enemy surface-to-air missiles (SAMs), which is a representative mission supported by electronic warfare. This paper develops a simulator for analyzing the effectiveness of SEAD missions under electronic warfare support using C++ language based on the DEVS (Discrete Event Systems Specification) model, the usefulness of which has been proved through case analysis with examples. The SEAD mission of the friendly forces is carried out in parallel with SSJ (Self Screening Jamming) electronic warfare under the support of SOJ (Stand Off Jamming) electronic warfare. The mission is assumed to be done after penetrating into the enemy area and firing HARM (High Speed Anti Radiation Missile). SAM response is assumed to comply mission under the degraded performance due to the electronic interference of the friendly SSJ and SOJ. The developed simulator allows various combinations of electronic warfare equipment specifications (parameters) and operational tactics (parameters or algorithms) to be input for the purpose of analysis of the effect of these combinations on the mission effectiveness.

• Korea Journal of Hospital Management
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• v.15 no.4
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• pp.165-190
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• 2010

Objectives : This study was supposed to investigate factors which influence to preference of medical tourism products of Japanese tourists in Seoul, Korea. Methods : Data were collected from 228 Japanese tourists who visited' Seoul Center for Culture & Tourism' in Myeong-dong, Seoul, Korea. We measured factors which influence to preference for medical tourism. The data were analyzed by T-test, ANOVA, and multiple regression analysis. Results : The major findings were as follows ; Japanese tourists preferred medical products in the order of skin care, oriental medicine treatment, health screening, and scaling & teeth whitening. They considered technical level of medical staff most importantly, followed by safety of medical products, communication during diagnosis and treatment, follow-up service, modernization of medical facilities and equipment, and the reasonable medical expenses. Japanese tourists' preferred medical institutions in the order of a university hospital, a specialty clinic, a special hospital, They said they intend to pay 50,000 to 150,000 yen for medical tourism. The preference to medical tourism products are that single women group in their twenties and thirties for skin care, married people group aged over thirties preferred oriental medicine treatment, and married men aged over forties and high income earners favored health screening. Conclusions : It should be considered carefully that the preference exists on some factors especially for Japanese tourist. Further research about preference on medical tourism products for tourists from the other countries is required appropriately to fulfill the needs.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.211-215
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• 2021

It is estimated that there are 40 million people with AIDS worldwide, with most cases occurring mainly in developing countries. HIV, the virus that causes AIDS, is infected with CD4+ T cells in the blood and gradually destroys CD4+ T cells for several months to 10 years, thereby lowering the patient's immune function. AIDS patients who have weakened immunity in this way will die from various diseases. The current method for counting the number of CD4+ T cells is usually performed by flow cytometry. The flow cytometry method has the advantage of high accuracy, but it is difficult to use in developing countries because it requires skilled professionals and equipment is expensive. As a result of this study, a device for AIDS screening was developed by capturing leukocytes from a small amount of 5 ㎕ blood through a microfilter and analyzing CD4+ T cells and CD8+ T cells from the captured cells. cheaper and easier to carry and use than current test equipment.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.2
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• pp.103-111
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• 2010

A total of 200 hospital employees participated in this study from January 2009 to June 2010. For the survey, each participant was given necessary items for external health exams. Cronbach's alpha was calculated for the survey regarding wireless networks. There was a need for educating data processing workers in the medical field regarding fundamental information prior to wireless network construction. The reason is high scores would be collected, which would reflect knowledge regarding data processing used at hospitals and the differences between paper charts and electronic charts. However, low scores were obtained which reflected knowledge regarding the differences between wired and wireless networks and Mini-PACS. Time for each patient was shortened to a maximum of three minutes and minimum of one minute for treatment and transmitting medical images when comparing pre and post wireless network construction(p < 0.01). Scores from the pre and post construction survey increase 1.98, 1.65, and 1.43 points for activity in the health screening area, usage of space in the health screening vehicle, and patient information storage respectively(p < 0.05). The number of patients receiving external health screenings twelve times was 3,655 prior to construction of a wireless network system. However, the number increased to 4,265 after construction. The increasing percentage was 17% in total. Prior to construction, X-ray images were taken 527 times, but after construction of a wireless network, this number growed to 1,194 and it was 116% increase. The loss of patient's medical treatment charts was reduced from 19.8% to 18.7% after construction. We believe that educating medical workers on Mini-PACS and Mini-OCS Systems will not only increase their efficiency but also make patients receiving better treatment.

• The Journal of the Korean Society for Microbiology
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• v.3 no.1
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• pp.15-23
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• 1968

For the effective control of Syphilis, many investigators have developed a more rapid, simple and economical screening serological test which is adequately sensitive and specific. To fulfill the requirements of a more rapid serologic test for syphlis, a substitute for the conventional serum specimen was needed since considerable time and labor are involved in the processing of blood to serum. Burdon suggested the use of plasma in the serologic tests for syphilis as a substitute for serum. He noticed that plasma was more sensitive than serum in the Kline and Kahn tests, and attributed this to the presence of more antibody-like substance, "reagin" in plasma than in serum. However, to make plasma sufficiently sensitive, it was necessary to inactivate plasma by heating at a temperature of $56^{\circ}C$ for about 30 minutes. Heating of plasma resulted in the precipitation of fibrinogen which made centrifugation necessary to obtain dear plasma. Since the chief disadvantage to the use of unheated plasma(or serum) was a reduction in sensitivity of results-which probably was due to a labile factor such as complement-Portnoy et al began to consider rapid chemical methods of inactivation of plasma(or serum). They experienced that choline chloirde was shown to be anticomplementary which suggested its use as an inactivating agent for unheated plasma(or serum). In 1959 Portnoy et al reported the Rapid Plasma Reagin(RPR) Test for syphilis which is a more rapid, economical and simple. But still this test has many disadvantages as a rapid performing, field and office procedure, because it requires the usual laboratory equipments such as centrifuge, rotating machine, microscope etc. To substitute these disadvantages of the RPR test, in 1962, Portnoy et al developed the Rapid Plasma Reagin(RPR) card test for syphilis, which has the following advantages: a) Simplicity and rapidity of performance, b) Requires no laboratory equipments, c) Stable antigen suspension, d) Adequate sensitivity and specificity. This RPR card test can be used as a rapidly performing and screening test in field investigation, outpatient clinics, small laboratories and hospitals doing limited syphilis serology, and predonor in blood bank. Private clinic which has limited laboratory equipment and technic for syphilis serology can also use this RPR card test as a tool in the rapid diagnosis of syphilis. It was thought that this RPR card test is a useful tool in Korea for private physician and mass survey for syphilis diagnosis. But Portnoy patented the reagents needed for the performing the RPR card test. Therefore authors developed newly the reagents and according to Portnoy's method evaluated the newly developed. RPR card test compared with the VDRL, Kolmer CF, and RPCF tests. The RPR card and VDRL tests were performed plasma and serum from the total 1,132 cases. Among these 1,131 cases, 521 were syphilis suspected laboratory specimens, and 611 were syphilis unsuspected healthy young men. After screening with these two tests, the RPR card and VDRL tests, reactive specimens to the above one or both tests were retested by the Kolmer CF and RPCF tests.

• Mass Spectrometry Letters
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• v.3 no.1
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• pp.25-28
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• 2012

Paint Spray is developed as a direct sampling ionisation method for mass spectrometric analysis of additives in polymer-based surface coatings. The technique simply involves applying an external high voltage (5 kV) to the wetted sample placed in front of the mass spectrometer inlet and represents a much simpler ionisation technique compared to those currently available. The capabilities of Paint Spray are demonstrated herein with the detection of four commercially available hindered amine light stabilisers; TINUVIN${(R)}$770, TINUVIN${(R)}$292, TINUVIN${(R)}$123 and TINUVIN${(R)}$152 directly from thermoset polyester-based coil coatings. Paint Spray requires no sample preparation or pre-treatment and combined with its simplicity requiring no specialised equipment makes it ideal for use by non-specialists. The application of Paint Spray for industrial use has significant potential as sample collection from a coil coating production line and Paint Spray ionisation could enable fast quality control screening at high sensitivity.