• Parasites, Hosts and Diseases
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• v.32 no.2
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• pp.93-100
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• 1994

In order to know the species and frequency of human parasitic infection diagnosed by biopsy, 149 cases (0.18%) of parasitic infection were reviewed, which were selected from 80,947 biopsied materials submitted for routine histopathological examination during a period of 10 years from 1980 to 1989 at Department of Pathology, Chonnam National University Hospital. They consisted of 112 cases of cysticercosis, 17 paragonimiasis, 7 clonorchiasis, 4 amebiasis, 1 sparganosis, 1 enterobiasis, 1 anisakiasis, and 1 fascioliasis respectively Based on morphological preservation of cysticercus, they could be divided into mild (20.2%), moderate (40.4%), and severe (39.4%) degeneration. Except 2 cases biopsied at the lungs, 15 cases of ectopic paragonimiasis were located at abdominal cavity (8 cases) and central nervous system (7 cases). One case of intrahepatic fascioliasis was observed. This is the 13th human fasciollasis reported in Korea. From the above results, the frequency of parasitic infections found in biopsied specimens was on the decrease as the year passed by, but biopsy is very useful diagnostic method on tissue parasites such as cystlcercosis and ectopic paragonimiasis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.10
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• pp.1029-1037
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• 2015

Recently, the importance of rotordynamic stability has been increased because of the tendency to employ ultra-high speeds in rotating machinery. In particular, the dynamic characteristics of gas bearings for high-speed rotating machinery need to be identified at various excitation frequencies to predict the rotor's behavior. In this study, we perform dynamic loading tests for gas-foil bearings (GFBs) to determine the bump foil structure and an air-film combined bump-foil structure for varying excitation frequencies. We calculate the dynamic characteristics from the measured force and displacement data. The air film is generated by a pressurized air supply. Based on the results, the stiffness coefficients of the bump structure and the air-film combined bump structure increased, while the damping coefficients decreased at increasing excitation frequencies. Further, the stiffness and damping coefficients of the air-film combined structure show lower values than those of the bump structure. Consequently, we identify the frequency-dependent dynamic characteristics of the bump structure and the effect of gas film on the dynamic characteristics of GFBs. Furthermore, to reveal the effectiveness of the proposed method, we perform experiments and discuss two methods of extracting the dynamic characteristics from the measured data.

• Toxicological Research
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• v.24 no.4
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• pp.273-280
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• 2008

The single intratracheal instillation (ITI) of bleomycin (BLM) is a widely used method for inducing experimental pulmonary fibrosis in rat model. In the present study, pulmonary function tests (PFTs) of tidal volume ($V_T$), minute volume ($V_M$), and respiratory frequency ($F_R$) have been applied to study their possibility as a tool to monitor the progress of BLM-induced lung injury in rat model. Rats were treated with a single ITI of BLM (2.5 mg/kg) or saline (control). Animals were euthanized at 3, 7, 14, 21, and 28 days post-ITI. Lung toxicity effects were evaluated by inflammatory cell count, lactate dehydrogenase (LDH) activity in the bronchoalveolar lavage fluid (BALF), and light microscopic examination of lung injury. The PFT parameters were measured immediately before the animals were sacrificed. BLM treatment induced significant cellular changes in BALF-increase in number of total cells, neutrophils, and lymphocytes along with sustained increase in number of macrophages compared to the controls at days 3, 7, and 14. BALF LDH level was significantly increased compared to that in the controls up to day 14. On day 3, infiltration of neutrophils was observed in the alveolar spaces. These changes developed into marked peribronchiolar and interstitial infiltration by inflammatory cells, and extensive thickening of the interalveolar septa on day 7. At 14, 21, and 28 days, mild peribronchiolar fibrosis was observed along with inflammatory cell infiltration. The results of PFT show significant consistencies compared to the results of other toxicity tests. These data demonstrate that the most suitable time point for assessing lung fibrosis in this model is 14 days post-ITI of BLM based on the observation of fibrosis at 14, 21, and 28 days. Further, the progress of lung injury can be traced by monitoring the PFT parameters of $F_R$, $V_T$, and $V_M$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.9
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• pp.809-819
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• 2004

In this paper, in order to exclude the expansion of M/W relay frequency or its new frequency assignment possibly, we analyzed a possibility of substituting M/W system by B-WLL or optical fiber network regarding service quality and economical points. To define the target of service quality, pre-condition and analysis method for the selected media have been derived to compare each other. E1 transmission with BER 10$^{-1}$ was chosen as a reference capacity, and service distance was calculated f3r the selected media as a function of availability. Also from the economical point we considered 3 systems such as optical fiber, M/W, and B-WLL based upon basic system structure, and analyzed them for various line configurations of fiber optic and B-WLL according to service period, system capacity, transmission distance, and data rate. It was confirmed that B-WLL can provide quality of service with 99.999 % availability within 1.6 km cell radius, and for optical fiber substitution, the leased fiber conduit on an electric pole is more economical than M/W system irrespective of service period, but in case of directly digging for underground conduit, it turned out ineffective regardless of cabling duct types.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.4
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• pp.247-255
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• 2018

In this work, glucose solution and sodium chloride solution were distinguished noninvasively using a microwave complementary split-ring resonator (CSRR). Based on the electrical properties of the two solutions measured using a open-ended coaxial probe, a CSRR was designed and fabricated for operation at a specific frequency that facilitates differentiating the two solutions. Furthermore, a polydimethylsiloxane mold was fabricated to concentrate the solution at a region where the electric field of the resonator was strongest, and a laminating film was used to prevent contact between the solution and resonator. Experiments were performed by dropping $50{\mu}L$ of the solution in steps of 100 mg/dL up to a maximum human blood glucose level of 400 mg/dL. Our experiments confirmed that the transmission coefficients ($S_{21}$) of glucose solution and sodium chloride solution exhibit variations of -0.06 dB and 0.14 dB, respectively, per 100 mg/dL concentration change at the resonance frequency. Thus, the opposite trends in the variation of $S_{21}$ with change in the concentration of the two solutions can be used to distinguish between them.

• Journal of the Korean Institute of Gas
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• v.16 no.1
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• pp.39-45
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• 2012

While the natural gas supply industry has continuously been growing, its potential hazard has also risen since the natural gas facilities essentially require installations that carry highly flammable and pressurized gas close to the populated areas, posing a serious consequence of significant property damage as well as human casualties in the event of accident. Therefore Quantitative Risk Assessment (QAR) has been recognized as a appropriate method to reduce the risk as far as possible, considering the reality of unachievable zero-risk. However, it is hard to perform effective QRA on hundreds of gas facilities because of insufficient number of expert and long-term analysis. In this paper, we suggest a conceptual QRA system framework to support more efficient risk analysis in gas supply facilities. In this system, the experts make questionnaires and internal calculation formula needed in accident frequency/consequence analysis of the facility through pre-analysis on the point of analysis, called incident point, and general users locate the point on the map and input the value required by the questionnaire to obtain the risk. Ultimately, this is suggested based on the idea that the specialization is available in QRA analysis process and the validity of the system is verified through actual system construction and application.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.691-697
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• 2009

Hardware dedicated off-the-shelf maritime differential GPS RSIM lacks the open architecture to meet all the minimum maritime user requirements and to include future GNSS improvements after recapitalization. This paper carries out a study to replace existing hardware dedicated differential GPS RSIM with software differential GPS RSIM in order to make up the weak point of hardware dedicated off-the-shelf maritime differential GPS RSIM. In this paper, the architecture of software RSIM is proposed for maritime DGPS recapitalization. And the feasibility analysis of the proposed software differential GPS RSIM is performed as the first phase to realize the proposed architecture. For the feasibility analysis, the prototype RF module and DSP module are implemented with properties as wide RF bandwidth, high sampling frequency, and high speed transmission interface. This paper shows that the proposed architecture has the possibility of real time operation of software RSIM functionality onto the PC-based platform through the analysis of computation time. Finally, this paper verifies that the L1/L2 dual frequency software differential RSIM designed according to the proposed method satisfies the performance specifications set out in RTCM paper 221-2006-SC104-STD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.701-711
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• 2000

To provide the baseline information for establishing community based nutritional service system in the context of health promotion, we conducted nutrition survey for 196 adults (male ; 99, female ; 97) in Kyungpook area. Individual food intake was measured by 24-hour recall method, and then diet quality was evaluated by Index of Nutritional Quality (INQ) and Mean Adequacy Ratio (MAR). Average dietary intake of Ca and Vit A of total subjects were lower than Korean Recommended Dietary Allowances (Ca; 83% of RDA, Vit A; 77% of RDA). On the whole, mean nutrients intake of male subjects were higher than that of female subjects. It also appeared that overall nutrients intake of younger women (20~29 yr) were lower than that of other age group. When we evaluated the nutrients intake of the subjects by INQ, Vit C (=2.39) showed the highest score. Ca (=0.89) and Vit A (=0.84) were revealed to be concerned nutrients in both quantity and quality. There was almost no difference in MAR between men and women (Men ; 0.88, Women ; 0.86). MAR showed significantrly positive correlation with age (p<0.05), meal frequency (p<0.001) and negative correlation with education level (p<0.01) in women, whereas no statistically significant relationship among these variables was observed in men. Age and meal frequency showed significantly positive correlation with most nutrients intakes among women. In conclusion, nutrition education strategies for sound food choice and regular meals need to be developed to improve the nutritional adequacy of female adults in the 20's.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.419-431
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• 2007

The setting of dental hygiene clinics is very important to dental hygiene education, which is the place not only to educate students but also to care clients. The purpose of this study is to provide basic research material for improvement of dental hygiene care system in dental hygiene clinics by analyzing the client satisfaction. A questionnaire survey by means of self-entry method was conducted to find out satisfaction of the client, who was visited to the dental hygiene clinics in the department of dental hygiene, Yonsei University. An analysis of frequency, one way ANOVA and T-Test were performed through SPSS 12.0K program. 1. Most clients were mainly composed of students in Wonju College of Medicine. 2. The clients visited for scaling(85.8%) and oral examination(9.73%) were much than treatment(4.42%). 3. Clients aged 21 to 25 were relatively lower in satisfaction with the facilities, system, attitude than any other ages. 4. The dental hygiene students are the lowest group in satisfaction with the facility, system, attitude than medical and nursing students. 5. The clients satisfaction with dental hygiene clinics was decreased in reverse proportion to visiting frequency. 6. Most of the clients pointed out the problems of appointment system(54.0%) and fee(23.0%), which should be improved than any other operation conditions. 7. Most of the clients were not satisfied with chair time and pain during care. 8. Most clients recognized to receive the better care service than other dental offices(81.3%). Especially, they paid attention to oral health education using phase-contrast microscope. 9. Many clients were dissatisfied with facilities of the dental hygiene clinics(71.7%). The problems of appointment system(54.0%) and chair time of dental hygiene care services(63.6%) had also inconvenienced to clients. The dental hygiene clinics in school play a crucial role in dental hygiene education to foster the student to be competent as a professional dental hygienist in the future. Therefore, well-organized dental hygiene care program based on dental hygiene process is essential. It is also required to improve the environment of dental hygiene clinics including facilities, appointment system and fee etc.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.2
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• pp.51-60
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• 2011

In this study, structural safety capacity analysis of the overpass railway bridge between Konkuk Univ. and Guui station railroad has been performed. The overpass is expected to have suffered durability reduction by deterioration. The weight reduction of the overpass has been implemented to prevent further durability reduction and to improve performance capacity. To reduce the weight, 3 procedures of replacing concrete soundproofing wall to light-weight soundproofing wall, replacing gravel ballast to concrete ballast, and reducing the weight of trough have been performed. The analysis of static/dynamic behaviors and improved capacity of the light-weighted overpass bridge has been performed. The structural safety verification of the improved structure has been implemented by using rating factors of load carrying capacity of PSC I girder. The results have shown that the deflection has been reduced by 2.6mm and tensile strength has been improved by 1.07MPa, which indicate that the structural capacity has effectively been improved. Also, the natural frequency has improved by approximately 30% where vibration reduction and dynamic behavior improvement have been achieved. Moreover, in the rating factor evaluation based on analysis and test results, an improvement from 1.82 to 1.93 has been observed. Therefore, weight reduction method for the overpass is effective considering overall results.