• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.836-842
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• 2011

The lateral stability of bridge foundations against train moving load, emergency stopping load, earthquakes, and so on is very important for a railway bridge foundation. A borehole test is much more accurate than laboratory tests since it is possible to minimize the disturbance of ground conditions on the test site. The representative borehole test methods are Dilatometer, Pressuremeter and Lateral Load Tester, which usually provide force-resistance characteristics in elastic range. In order to estimate P-y curves using those methods, the non-linear characteristics of soil which is one of the most important characteristics of the soil cannot be obtained. Therefore, P-y curves are estimated usually using elastic modulus ($E_O$, $E_R$) of lateral pressure-deformation ratio obtained within the range of elastic behavior. Even though the pile foundation is designed using borehole tests in field to increase design accuracy, it is necessary to use a higher safety factor to improve the reliability of the design. A Large Displacement Borehole Testmeter(LDBT) is developed to measure nonlinear characteristics of the soil in this study. P-y curves can be directly achieved from the developed equipment. Comparisons between measured P-y curves the LDBT developed equipment, theoretical methods based on geotechnical investigations, and back-calculated P-y curves from field tests are shown in this paper. The research result shows that the measured P-y curves using LDBT can be properly matched with back-calculated P-y curves from filed tests by applying scale effects for sand and clay, respectively.

• Journal of Microbiology and Biotechnology
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• 제22권8호
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• pp.1155-1160
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• 2012

Sulfur-utilizing autotrophic denitrification relies on an inorganic carbon source to reduce the nitrate by producing sulfuric acid as an end product and can be used for the treatment of wastewaters containing high levels of nitrates. In this study, sulfur-denitrifying bacteria were used in anoxic batch tests with sulfur as the electron donor and nitrate as the electron acceptor. Various medium components were tested under different conditions. Sulfur denitrification can drop the medium pH by producing acid, thus stopping the process half way. To control this mechanism, a 2:1 ratio of sulfur to oyster shell powder was used. Oyster shell powder addition to a sulfur-denitrifying reactor completely removed the nitrate. Using 50, 100, and 200 g of sulfur particles, reaction rate constants of 5.33, 6.29, and $7.96mg^{1/2}/l^{1/2}{\cdot}h$ were obtained, respectively; and using 200 g of sulfur particles showed the highest nitrate removal rates. For different sulfur particle sizes ranging from small (0.85-2.0 mm), medium (2.0-4.0 mm), and large (4.0-4.75 mm), reaction rate constants of 31.56, 10.88, and $6.23mg^{1/2}/l^{1/2}{\cdot}h$ were calculated. The fastest nitrate removal rate was observed for the smallest particle size. Addition of chemical oxygen demand (COD), methanol as the external carbon source, with the autotrophic denitrification in sufficiently alkaline conditions, created a balance between heterotrophic denitrification (which raises the pH) and sulfur-utilizing autotrophic denitrification, which lowers the pH.

• Applied Biological Chemistry
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• 제36권1호
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• pp.7-10
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• 1993

ELISA법을 zearalenone 생성균주 검색에 응용하였다. 먼저 zearalenone에 대한 항체를 500배 희석한 후 microtiter well에 $125\;{\mu}l$씩 주입하여 $40^{\circ}C$에서 overnight시켜 coating하고, 시료용액과 enzyme을 $37^{\circ}C$에서 30분간 반응시켰다. 배양후 washing buffer로 6회 세척한 다음 plate에 2,2'-azino-di-3-ethyl-benzthiazoline sulfonic acid(ABTS) 용액을 $100\;{\mu}l$씩 첨가하여 15분간 발색시킨 다음 반응 정지액 $100\;{\mu}l$씩을 가해 반응을 정지시키고 ELISA Reader로서 흡광도(410 nm)를 측정하였다. 그 결과 zearalenone 생성이 확인된 19 균주 중 분리균 R-5, C-46 및 S-134가 50 ng/ml 이상의 zearalenone을 생성하였다.

• 한국정밀공학회지
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• 제6권2호
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• pp.40-46
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• 1989

Recently, the researches on cutting the new material have been done for development of aerospace industrial engineering. Especially, titanium ally is well known as heat resisting, antiwear, anticorrosion and difficult-to-machine materials. Many studies on the analysis of shear angle have been done for improving productivity in cutting these materials. In case of titanium alloy, the saw-toothed type of chip which has wave surface of a triangular form, an eccentric from of a continuous type of chip that is produced in the cutting process, was checked. Nakayama supposed that a maximum shear strewss plane and the shear crack in the free surface made an angle of $45^{\circ}$ .deg. , but it's usually much larger than that. In this paper, the author analyzed the shear conditions of the cutting process in the quick-stopping device with the help SEM-photographs, and measured the hypotenuse angle directly in the photographs of the chips. In conclusion, the author tried to find the shear angle in the cutting process with the saw-toothed chip and compared it with the shear angles which can be calculated from the theories established by others. The results obtained are as follows. 1. In case of the saw-toothed chips, the equivalent cutting ratio can be calculated by using the chip thickness to two-thirds of ramp height. 2. The theory of Ernst-Merchant is not applicable to the titanium and its alloys which does not fractured in accordance with the theory of maximum shear stress. 3. When we cut the titanium alloys which produced the saw-toothed chips, the shear angle can be found with the theories of Rowe-Spick, P.K. Wright and the measurement of hypotenuse angle.

• 대한기계학회논문집B
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• 제36권5호
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• pp.465-475
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• 2012

본 연구는 두 가지 목표를 가지고 수행하였다. 하나는 수치해석과 Design-FOIL Pro.를 이용해 블레이드 에어포일 모델개발이고, 다른 하나는 이 모델을 Folding blade에 적용하는 것이다. 일반적으로 1MW이상 대형풍력터빈용 블레이드는 강풍시에 피칭제어로 풍향에 대해서 평형상태를 유지하여 로터를 회전시키지 않는 방법으로 블레이드의 손상을 방지 하였지만, 소형풍력터빈용 블레이드는 설비비, 유지비등 경제성을 이유로 피칭제어를 채택하지 않아 블레이드의 파손 문제가 심각하다. 그래서 본 연구에서는 유지보수가 필요 없고 강풍에서도 파손이 없는 Spring pack을 이용한 로터를 직접설계(Direct-Design) 방법으로 설계하여, 그 성능을 검증 하고 변화 풍속에 맞는 폴딩각을 이용해 강풍시에도 Wind turbine이 Cut-out 없이 계속발전을 유지할 수 있도록 하는 점에 집중 연구하고자 한다.

• Clinical and Experimental Pediatrics
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• 제61권3호
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• pp.95-100
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• 2018

Purpose: This study aimed to evaluate the clinical findings in pediatric rhabdomyolysis and the predictive factors for acute kidney injury (AKI) in Korean children. Methods: Medical records of 39 Korean children, who were newly diagnosed with rhabdomyolysis from January 2008 to December 2015, were retrospectively analyzed. The diagnosis was made from the medical history, elevated serum creatinine kinase level >1,000 IU/L, and plasma myoglobin level >150 ng/mL. Patients with muscular dystrophy and myocardial infarction were excluded. Results: The median patient age at diagnosis was 14.0 years (range, 3-18 years), and the male to female ratio was 2.5. The most common presenting symptom was myalgia (n=25, 64.1%), and 14 patients (35.9%) had rhabdomyolysis-induced AKI. Eighteen patients (46.2%) had underlying diseases, such as epilepsy and psychotic disorders. Ten of these patients showed rhabdomyolysis-induced AKI. The common causes of rhabdomyolysis were infection (n=12, 30.7%), exercise (n=9, 23.1%), and trauma (n=8, 20.5%). There was no difference in the distribution of etiology between AKI and non-AKI groups. Five patients in the AKI group showed complete recovery of renal function after stopping renal replacement therapy. The median length of hospitalization was 7.0 days, and no mortality was reported. Compared with the non-AKI group, the AKI group showed higher levels of peak creatinine kinase and myoglobin, without statistical significance. Conclusion: The clinical characteristics of pediatric rhabdomyolysis differ from those observed in adult patients. Children with underlying diseases are more vulnerable to rhabdomyolysis-induced AKI. AKI more likely develops in the presence of a high degree of albuminuria.

• Urogenital Tract Infection
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• 제13권3호
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• pp.79-83
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• 2018

Purpose: The 5 alpha reductase inhibitor (5ARI) reduces the size of the prostate and alleviates lower urinary tract symptoms. After stopping 5ARI, the prostate quickly recovers to its pre-medication size. The purpose of this study was to investigate the factors affecting the restoration of prostate size after 5ARI discontinuation. Materials and Methods: Between March 2009 and May 2017, patients who visited an outpatient clinic and were diagnosed with benign prostatic hyperplasia were selected and start 5ARI medication. After 6 months of medication, the patients stopped medication for 1 year. Meanwhile, we measured the prostate volumes of patients 3 times (before and after medication, after discontinuation) and divide the patients into 3 groups (maintained, intermediate, and restored) with recovered prostate volume ratio. After classification, we investigated the relationship between the variable factors (age, serum prostate-specific antigen, initial volume, reduced volume after medication) between groups. Results: Among the 147 selected patients, the mean age and plasma PSA level were $61.6{\pm}7.9$ and $0.8{\pm}0.6$, respectively. The mean initial prostate volume was $32.3{\pm}4.2ml$, which reduced to $23.2{\pm}3.2ml$ after medication. After one year of discontinuation, the mean volume was $31.4{\pm}6.4ml$, with restoration to 101.5% of the reduced size. We noticed a tendency that patients with faster prostate volume recovery were generally older than those with slower recovery; however, this was not statistically significant. Other factors showed no relationship with prostate recovery. Conclusions: When using 5ARI in elderly patients, continuous treatment seems better than intermittent treatment. If discontinuation is needed, short term follow-up is recommended.

• 한국간호교육학회지
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• 제7권1호
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• pp.38-53
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• 2001

The main purpose of this study was to present the basic materials that help the nursing of the infants and consultation of childcare by examinating the knowledge and practice of the mothers about the weaning diet. The data for this study was collected from 205 mothers with infants(6-36 months) who visited two hospitals or one university hospital in Seoul, who were living in one apartment Suwon area between July. 7. and September 10, 2000. The 57 questionnaires were used for collecting the data and SAS program was used to analyse the data. The results are as follows. 1. The items of low score in the result of the knowledge data were as follows. [Initial weaning time, the important nutritional problem in infant, considering factor during feeding, the relation of proper weaning food & age, the time of used by cup, to apply of proper spicies in weaning food, the time of completing weaning, the time of stopping weaning at abnormal sign, and the inappopriate reason of dry mixed powdered food (Sunsik) as a weaning food.] 2. Higher educated mothers presented more high score than lower educated mothers in the knowledge about the weaning. (p<0.05) 3. Before the weaning, more mothers were using the commercial milk (51.2%) than the breast milk (13.2%). 4. Mothers get the knowledge about the weaning from the infants care book of cook books(26.4%). 68% of mothers had not received any consulting service with regard to the weaning, 10.2% of them consulted Pediatrician about the weaning and 0.5% of them with nurse. 5. Most mothers began supplymentary food, from four to six months (65.4%). the ratio was about the same as the ratio of mothers who knEw the appropriate time for the introduction of supplymentary food(83.2%) 6. The main solid food was commercial food, not home-prepared food. 7. Higher educated mothers used home-prepared weaning food more often than lower educated mothers(P<0.05). 8. The used rate by spoon was 57.4%, but the rate of mother's knowledge data was 95.0%. 9. The time of completing the weaning was in 12-18 months(53.8%). It is similar to the mother's knowledge data(52.7%) Conclusion ; According to knowledge data, it turns out that most mothers know moderatly about the weaning (everage 60/100). However their knowledge and practice on the methods & procedures on the weaning were inadquate. Especially, most mothers did not consult with those qualification about the weaning. Therefore, the role of the nurse as a provider of information on the weaning should be emphasized with varied educational programs in many health care center.

• 한국의학물리학회지:의학물리
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• 제28권4호
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• pp.207-217
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• 2017

For effective patient treatment in proton therapy, it is therefore important to accurately measure the beam range. For measuring beam range, various researchers determine the beam range by measuring the prompt gammas generated during nuclear reactions of protons with materials. However, the accuracy of the beam range determination can be lowered in heterogeneous phantoms, because of the differences with respect to the prompt gamma production depending on the properties of the material. In this research, to improve the beam range determination in a heterogeneous phantom, we derived a formula to correct the prompt-gamma distribution using the ratio of the prompt gamma production, stopping power, and density obtained for each material. Then, the prompt-gamma distributions were acquired by a multi-slit prompt-gamma camera on various kinds of heterogeneous phantoms using a Geant4 Monte Carlo simulation, and the deduced formula was applied to the prompt-gamma distributions. For the case involving the phantom having bone-equivalent material in the soft tissue-equivalent material, it was confirmed that compared to the actual range, the determined ranges were relatively accurate both before and after correction. In the case of a phantom having the lung-equivalent material in the soft tissue-equivalent material, although the maximum error before correction was 18.7 mm, the difference was very large. However, when the correction method was applied, the accuracy was significantly improved by a maximum error of 4.1 mm. Moreover, for a phantom that was constructed based on CT data, after applying the calibration method, the beam range could be generally determined within an error of 2.5 mm. Simulation results confirmed the potential to determine the beam range with high accuracy in heterogeneous phantoms by applying the proposed correction method. In future, these methods will be verified by performing experiments using a therapeutic proton beam.

• 한국실내디자인학회논문집
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• 제20권4호
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• pp.174-182
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• 2011

This study analyzed visitors' behaviors in the viewpoint of Attraction Power and Holding Power of exhibits on the basis of exhibition layout of real science museums. Through the analysis, the study grasped efficiency of analysis index and exhibition environment elements which might have an effect on planning the exhibition space of a large-scale museum and producing detailed ranges of exhibition. The main indicators used are: 1. Attraction Power: it indicates the relative incidence of people who have stopped in front of an object/exhibit during the exhibition tour. It is calculated by dividing the number of people who stop by the total number of people who have visited the museum or gallery. 2. Holding Power: it measures the average time spent in front of an information/communication element. It is calculated by dividing the average time of stay by the time "necessary" to read an element. As a result of analyzing the exhibition areas of National Science Museum (Daejeon) and National Museum of Emerging Science and Innovation(Tokyo), the Holding Power was found to be relatively lower than the Attracting Power. This means that 3.5 out of 10 visitors stop in front of the exhibit in 6 exhibition areas, and among these, only 1/10 is used when compared to the user required time of the exhibits. In other words, like the method of deriving an analysis index, the stage of viewing can be categorized as Attracting Power and Holding Power, and because the stage from Attracting Power to the stage of Holding Power are strongly linked, it shows that it is not easy to display a meaningful result. Except, the general distribution of Attracting Power was shown to be high from the entrance area of the exhibition hall based on the standard of viewing sequence. Also, the Holding Power became sequentially lower according to the sequence of exhibition viewing and displayed a meaningful interrelationship with the distribution ratio of island exhibits. In the case of island exhibition method, it is less influenced by the movement flow of visitors when compared to the wall type method of exhibition and can be understood as an exhibition method that provides spatial chances enabling stopping and viewing.